As the name entails
 Are partial to mammals
  Especially other animals
   Deer and seals
    All become meals
     Also white shark
    Reality quite stark
   Top ocean predator
  A killing pre-meditator
Kills efficient
 Not complacent
  Tall dorsal pose
   Brings ocean of prose
    Life at sea
   Efficiently
  Close knit family
 All related genetically
Range afar
 As pantry ajar
  Seeing takeaway meals
   Plays with seals
    Kind side of matriarch
     Young calves play the lark
    Frolic in the open ocean
   Dorsal strong with constant motion
  Hope to see black dorsals tall
 Now we've seen your signals small
Intriguing sound
 On Sonix found
  Not complex
   Small intonation flex
    We seek the lion of the sea
     A truly oceanic beasty